A) Erosion by glaciers during the Pleistocene epoch.
B) Tectonic uplift in the Cenozoic era.
C) Volcanic activity during the Mesozoic era.
D) The collision of continental plates about 150 million years ago.

A) The Illinoian Glaciation.
B) The Wisconsinan Glaciation.
C) The Vashon Glaciation, which lasted from about 19,000 – 16,000 BP.
D) The Pinedale Glaciation.

A) Great Salt Lake.
B) Lake Erie.
C) Lake Michigan.
D) The Salish Sea.

A) Appalachian Mountains and Cascade Range.
B) Pacific Ranges and Vancouver Island Ranges.
C) Cordillera Blanca and Andes.
D) Rocky Mountains and Sierra Nevada.

A) Glacially striated tablelands and rolling hills underlain by sedimentary rocks.
B) Sand dunes and desert basins.
C) Karst topography with limestone caves.
D) Volcanic mountains and lava plateaus.

A) Chernozem and podzol.
B) Lateritic soils and peat bogs.
C) Soils formed from glacial till, glacial outwash, and Lacustrine deposits.
D) Alluvial soils and loess.

A) Great Plains and Mississippi Alluvial Plain.
B) Fraser Lowland, Nanaimo and Nahwitti lowlands of Vancouver Island.
C) Pocono Plateau and Allegheny Plateau.
D) Ozark Plateau and Black Hills.

A) The Puget Sound basin.
B) Columbia Basin.
C) Colorado Plateau.
D) Great Basin.

A) Hudson Bay.
B) Bering Sea.
C) Salish Sea.
D) Gulf of Mexico.

A) Earthquakes and volcanic eruptions.
B) Industrialization, agriculture, forestry, urbanization, and suburban sprawl.
C) Natural wildfires and droughts.
D) Asteroid impacts.

A) Extreme elevation.
B) Low elevation.
C) High elevation.
D) Variable elevation.